1. Field of the Invention:
There are two types of button perforating sewing machines. The first type perforates cloth in an earlier step (hereinafter referred to as earlier perforation type). The second type perforates cloth in a later step (hereinafter referred to as later perforation type).
The present invention relates to a cutter actuator for a button perforating sewing machine which can function as either the first type or the second type machine.
2. Description of Prior Art:
One cycle of a series of successive perforating operations in the earlier perforation type machine comprises "SEWN CLOTH CLAMPING STEP", "BUTTON PERFORATING STEP", "CLOTH TENSIONING STEP", "FIRST FEEDING STEP", "SEWING STEP", "SECOND FEEDING STEP", and "SEWN CLOTH CLAMPING AND RELEASING STEP". One cycle in the later perforation type machine comprises "SEWN CLOTH CLAMPING STEP", "CLOTH TENSIONING STEP", "FIRST FEEDING STEP", "SEWING STEP", "SECOND FEEDING STEP", "BUTTON PERFORATING STEP", and "SEWN CLOTH CLAMPING AND RELEASING STEP".
The earlier perforation type differs from the later perforation type with respect to the order or the position of "BUTTON PERFORATING STEP" in the cycle.
"BUTTON PERFORATING STEP" in the prior art later perforating type machine will be described with reference to FIG. 6.
As shown in FIG. 6, a kick plate shaft 100 secured to a gear rotatable for one revolution at one cycle is turned in the direction of the dotted arrow a at the last stage of the cycle (SECOND FEEDING STEP) thereby pushing a pin 104 of a kick plate 103. As a result, a kick plate carrier 1 integrated with the kick plate 103 is rotated, causing a cutting actuator lever 8 connected to a kick plate carrier shaft 2 to swing in the direction shown by arrow F.
"BUTTON PERFORATING STEP" of the prior art earlier perforation type machine is shown in FIGS. 4, 5. As shown in these Figures, a cutting actuator lever kick plate 101 is fixed to the closing lever 22 which operates during the "SEWN CLOTH CLAMPING STEP". Upon swinging movement of the closing lever 22 about the axis of E--E', a projection 102 of the cutting actuator lever 101 pushes the cutting actuator arm 25' (refer to FIG. 5) while the cutting actuator lever 8 is turned in the direction of the arrow F.
In either case, the invention shown in FIG. 2 employs the swinging movement of cutting actuator lever 8 in the direction of F, causes block 9 to be disengaged from a right projection 10a of clutch 12 slidably attached to a cutting driven wheel 15 while clutch 12 is urged by a spiral spring 11 to move radially. A left projection 10b of the clutch 12 is connected to one of the cutting wheel blocks 13 fixed to an inner peripheral surface of a cutting wheel 14 which is always rotated beside the cutting driven wheel 15. As a result, the cutting driven wheel 15 starts to rotate together with the cutting driving wheel 14. With the rotation of the cutting driven wheel 15, the cutting driven wheel 15 and a pair of cams 16, 16' connected to the driven wheel 15 via a cutting axis G--G' are rotated thereby causing a pair of cutting arms 17, 18 to swing whereby a woven cloth 31 is subjected to the button perforating operation by a block 20 and a knife 19 secured to one end of the pair of cutting arms 17, 18.
When one sewing machine is to function either as an earlier type machine or as a later type machine, a plurality of switching operations are required. That is, if the earlier perforation type is switched to the later perforation type, it was necessary to engage the kick plate carrier shaft 2 with the cutting actuator lever 8 by actuating a holder (not shown) which slightly moves upward the cutting actuator kick plate 101 so that the projection 102 of the cutting actuator lever kick plate 101 does not push the cutting actuator arm 25' while the knife 19 is operated at the operation timing of the earlier perforation type in a first "SEWN CLOTH CLAMPING STEP" in one cycle operation. Namely, in a substantially last step of the earlier perforation type, the kick plate carrier shaft 2 is pulled forwardly to be drawn into the kick plate carrier 1 in order that a cutting actuator lever plate 7 is not operated even if the kick plate shaft 100 operates the kick plate 103 while the swinging movement of the kick plate carrier shaft 2 is not delivered to the cutting actuator lever 8.
In the case of switching from the later perforation type to the earlier perforation type, an operation as reversed to the switching from the earlier perforation type to the later perforation type is required.
Thus, in order to provide the single sewing machine with both earlier and the later perforation type functions it is necessary to deal with various problems. In the first place, the structure is complex since both the cutting actuator lever kick plate 101 and the kick plate carrier shaft 2 are drivable. Secondly, the switching operation between the earlier perforation type and the later perforation type is troublesome. Thirdly, there is a risk that the sewn cloth 31 and the sewing machine can be damaged should an operator forget to carry out the switching operation between the earlier perforation type and the later perforation type.